Earlier this week Ghosn told a Tokyo court he was innocent, in his first public appearance since his arrest, and appealed for his detention to end. But the court rejected the request.

“I have a genuine love and appreciation for Nissan,” Ghosn told the court.

“In all of my efforts on behalf of the company, I have acted honourably, legally and with the knowledge and approval of the appropriate executives inside the company.”

He said the compensation was never decided on, the investment deal did not result in any losses to Nissan, and the payments to the Saudi businessman was for legitimate services related to dealers and investments in the Gulf.

Ghosn, who appeared much thinner than before his arrest, came down with a fever the day after his court appearance, but has since recovered, his lawyer Motonari Ohtsuru said.

His wife Carole Ghosn has issued a statement expressing concern over his illness.

Ghosn’s lawyer, Motonari Otsuru (AP)

“I am pleading with the Japanese authorities to provide us with any information at all about my husband’s health. We are fearful and very worried his recovery will be complicated while he continues to endure such harsh conditions and unfair treatment,” she said.

Before his sudden downfall, Ghosn was a respected figure in the global car industry, having rescued the Japanese firm from near-bankruptcy, building its sales operations and profits and pioneering ecological vehicles.

Nissan said an internal investigation began in the middle of last year after whistleblowers came forward.

Chief executive Hiroto Saikawa has denounced Ghosn, accusing him of using company money and assets for personal gain.

Ethics officials at Nissan’s alliance partner Renault SA of France concluded this week that financial compensation to members of the French carmaker’s executive committee in 2017 and 2018 was fraud-free.

The review was initiated after Ghosn was arrested. Ghosn remains CEO of Renault.